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Flat Battery Experience


Go to solution Solved by stepppy,

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All my own fault but wanted to share this with any newbie petrol hybrid/LBX owners.

Today, I was sat in the car waiting for my wife who was in a Tesco. I thought I'd listen to the radio. After about 20 minutes, the radio stopped just as I opened the boot seeing her walk back to car. The boot door wouldn't then lock shut. Couldn't close the open windows either as it started to drizzle. Wife couldn't open the passenger door either. I had to pull on the lever (not the usual push) to get out. Having the windows stuck open helped as the doors couldn't be opened from the outside without leaning in (in the panic, you forget about the metal key hidden inside the fob). RAC couldn't come for hours but fortunately remembered a friend lived nearby.

Then the fun started. Open the bonnet and where is the Battery for a jump start? An ex mechanic pops by, "where's the chuffin Battery?" 😀Of course the diabolicaly indexed so called manual supplied is a nightmare to try find anything in a crisis. Eventually we find that you have to take the plastic cover off the box in the top right hand side of the engine bay marked "Relay and Fuse" and lift a small red clip to access the positive, then you have to find a good contact spot for the negative. Hey presto, we get going.

As I said, my fault so don't listen to any music, radio etc in just accessory mode. I must have missed reading that but it is strongly advised. Naivety strikes again!!

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Very helpful and totally agree that the so called manual is useless and not sure who the intended "audience" are. Certainly useless indexing for "old school". Have discovered the "proper" manual is called DFOM and can be found on the website alongside the manuals for dummies (but they must be clever dummies to make sense of it!). Shame Lexus do not provide the DFOM in hard copy to new owners as I am sure it would solve many queries.

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4 hours ago, guinchy said:

All my own fault but wanted to share this with any newbie petrol hybrid/LBX owners.

Today, I was sat in the car waiting for my wife who was in a Tesco. I thought I'd listen to the radio. After about 20 minutes, the radio stopped just as I opened the boot seeing her walk back to car. The boot door wouldn't then lock shut. Couldn't close the open windows either as it started to drizzle. Wife couldn't open the passenger door either. I had to pull on the lever (not the usual push) to get out. Having the windows stuck open helped as the doors couldn't be opened from the outside without leaning in (in the panic, you forget about the metal key hidden inside the fob). RAC couldn't come for hours but fortunately remembered a friend lived nearby.

Then the fun started. Open the bonnet and where is the battery for a jump start? An ex mechanic pops by, "where's the chuffin battery?" 😀Of course the diabolicaly indexed so called manual supplied is a nightmare to try find anything in a crisis. Eventually we find that you have to take the plastic cover off the box in the top right hand side of the engine bay marked "Relay and Fuse" and lift a small red clip to access the positive, then you have to find a good contact spot for the negative. Hey presto, we get going.

As I said, my fault so don't listen to any music, radio etc in just accessory mode. I must have missed reading that but it is strongly advised. Naivety strikes again!!

I'm sorry for the problems you had but come on, it could have all been avoided by reading the manual, especially if you've never had a hybrid before because they're very different to a conventional car.

Even though I've been driving for 49 years and am fully conversant with the workings of a conventional car, I read the manual from cover to cover during the week the dealer was prepping the car for me to pick up and it was well worth it.

Owners must take some responsibility (and I acknowledge that you said it was your fault) when moving to a hybrid or it could be both embarassing and expensive.

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I’ve had hybrids for years and I was caught out by this last weekend. I didn’t sit in the car with the radio on etc. but I had left it on the drive and been out a couple of times during the day. Was locked each time, then I backed out to turn the car around so I could put stuff in for some painting and after loading my stuff tried to move it. All the clicking and pulsing started and that was it. After I got out, the car wouldn’t open so I called the AA. Got told off too lol!

I asked the dealer if they’d had issues and it’s a common hybrid thing. They changed the Battery and speaking to a Toyota mastertech friend, he says that they are modifying the batteries to try and get them to hold more charge. 
 

So leave it on READY if you’re waiting etc. 

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I helped a friend move house this week and my NX spent a lot of time with the tailgate and rear doors opened whilst I loaded it with various items and I had no issues. 

After approx 10 minutes the interior lights automatically turn off just like several of my cars before it did.

Opened and closed the tailgate several times too. I did this about three times during the day and all was well. 

If I am sat in the car doing any changes to menus etc. I will always put the car in ready mode and press the EV button to stop the ICE starting, but I didn’t do that with the various loading/ unloading trips I did. I did have my jump pack with me just in case.

I am not sure why some cars seem to have issues and others do not. 

As it has been said many times here, anytime you are sat in the car using radio etc. always put it in Ready mode. 

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Wot a ridiculous pullava we’ve ( well you anyway ) have landed yourselves with up-to-the-minute modern day challenging motoring ……. it’s totally barmy, nuts of the highest order …… what one goes thru’ with new tech car motoring 

…….. despairing for you all suffering these modern trials and tribulations …….. how far forward has one leapt in motoring ( in ) convenience 

 

Sorry, ignore me …… I’ll stay as I am for so long as tenable 🤞

Malc 

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Hi Paul. If you read my post about possible problems with the LBX 12v Battery, I am afraid to say it's not uncommon. As most have said when in the car and in a hybrid always best to leave the car in "ready" mode so the traction Battery can charge the 12v Battery

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10 hours ago, Herbie said:

 

Even though I've been driving for 49 years and am fully conversant with the workings of a conventional car, I read the manual from cover to cover during the week the 

Here Here Herbie.I believe the appropriate acronym is RTFM.

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How odd - if I'm sitting in Cordelia with the radio playing and the engine's off, it will automatically shut everything down after about 15-20 minutes to save the Battery.

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9 minutes ago, Mincey said:

How odd - if I'm sitting in Cordelia with the radio playing and the engine's off, it will automatically shut everything down after about 15-20 minutes to save the battery.

Yes, that’s the same as I mentioned about interior lights, but I think the OP was using accessory mode and not ready mode and that’s what causes the issue. 

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38 minutes ago, stepppy said:

Yes, that’s the same as I mentioned about interior lights, but I think the OP was using accessory mode and not ready mode and that’s what causes the issue. 

Ah ok - that makes sense.

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Wouldn’t it be more sensible for Lexus to simply install a bigger and better Battery in the first place? The difference in cost between a low capacity 12V Battery and a more conventional one is insignificant in comparison to the price of the car.

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15 minutes ago, Expatma said:

Wouldn’t it be more sensible for Lexus to simply install a bigger and better battery in the first place? The difference in cost between a low capacity 12V battery and a more conventional one is insignificant in comparison to the price of the car.

On the face of it that sounds sensible. But marginal gains in multiple areas across 10,000s of vehicles adds up to quite a financial saving. There is also the space and weight saving that the smaller Battery provides. 

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22 hours ago, Malc1 said:

Wot a ridiculous pullava we’ve ( well you anyway ) have landed yourselves with up-to-the-minute modern day challenging motoring ……. it’s totally barmy, nuts of the highest order …… what one goes thru’ with new tech car motoring 

Sorry Malc but I have to tell you it is "palaver" A pullava is a cardigan without a zip.

But I totally agree. Starting and using a car should be intuitive and not complicated. Idiot-proof is a good way to go. Pensioner proof is a different problem.  I think it is sufficient and common sense to just be in Park mode, press the brake and push "start". Also, the stand-by function should be enough to turn things off when there is a risk of draining the Battery before it gets too late.  KISS and RTFM are good acronyms.  WTF!

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1 hour ago, GMB said:

Idiot-proof is a good way to go. Pensioner proof is a different problem

Not sure what you mean by Pensioner proof, I am a pensioner and I have never had a problem so it must be 🤪

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  • 2 weeks later...
On 8/16/2024 at 9:51 AM, Steve7458 said:

I have all ways carried a NOCO boost since my flat battery days in RC's and UX cars, little pricey but gets you out of problems very quickly. Highly recommended 

What ampage is on your noco boost. I see they start at 500amps but not much more for the 1000amp. Maybe a smart buy before the winter months?

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7 minutes ago, kevinc23 said:

What ampage is on your noco boost. I see they start at 500amps but not much more for the 1000amp. Maybe a smart buy before the winter months?

You only need 20 amps for a hybrid to get it into Ready mode as the engine isn't started by the 12v supply, just the onboard computers need to be powered up. Purchase the smallest jump starter you need to cover any other use (e.g. other vehicles in your household).

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On 8/27/2024 at 8:18 AM, ColinBarber said:

You only need 20 amps for a hybrid to get it into Ready mode as the engine isn't started by the 12v supply, just the onboard computers need to be powered up. Purchase the smallest jump starter you need to cover any other use (e.g. other vehicles in your household)./

So when you are driving your LBX as per normal, what then starts the ICE engine, the 12v or traction? And what is draining peoples 12v Battery surely it can't just be computer gizmos? Do the headlights also use the 12v system which in my experience is the main flat Battery culprit. 

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The computer starts the engine and I think people not putting car in ready mode when listening to radio, having door open while cleaning but I do that on my UX without problems, must be a lot smaller Battery.

Dell

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4 hours ago, lexuswannabe said:

So when you are driving your LBX as per normal, what then starts the ICE engine, the 12v or traction? And what is draining peoples 12v battery surely it can't just be computer gizmos? Do the headlights also use the 12v system which in my experience is the main flat battery culprit. 

If the car is in Ready mode the traction Battery will provide all power needed for electrical items including starting the ICE as needed. The 12V Battery will also be charged from the traction Battery when the car is in Ready mode. The ICE will also be started to recharge the traction Battery as needed. So the only kinit6on how long the car can remain in Ready state is when the petrol runs out. The 12v Battery takes over providing all electrical accessories (radio, lights etc) if the car is not in Ready mode or the car is left in N (so always leave it in P or D when stopped and never N and if sitting in the car or doors are open always start it into Ready mode if any electrical items are on for any length of time - even interior lights). 

Any 12V Battery has a limited capacity and all cars draw some current when left such as the car alarm etc. Hybrid batteries tend to be a bit smaller as hybrid cars need less capacity for normal usage. But if the car is used regularly (eg at least once a week for a couple of hours a week) you will have no problem with the 12V Battery. My IS 300h is nearly 10 years old with 150k miles on it and still on the original Battery. My wife's Yaris is 5 years old with 20K miles and still on the original Battery. Both cars have no issues but are at different ends of usage but even the Yaris gets used once a week. 

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1 hour ago, wharfhouse said:

or the car is left in N (so always leave it in P or D when stopped and never N and if sitting in the car or doors are open always start it into Ready mode if any electrical items are on for any length of time - even interior lights). 

Technically the hybrid system is still providing all electrical power for the vehicle when in N (the system is still in Ready mode). The issue is that when the hybrid/traction Battery gets low the petrol engine cannot recharge and you therefore run the risk of fully discharging the Battery which is very bad (although I'm sure the vehicle will just shut down before that happens).

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1 hour ago, ColinBarber said:

Technically the hybrid system is still providing all electrical power for the vehicle when in N (the system is still in Ready mode). The issue is that when the hybrid/traction battery gets low the petrol engine cannot recharge and you therefore run the risk of fully discharging the battery which is very bad (although I'm sure the vehicle will just shut down before that happens).

Thanks for clarifying - I didn't put that part very well in my message.

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8 hours ago, lexuswannabe said:

So when you are driving your LBX as per normal, what then starts the ICE engine, the 12v or traction?

The traction Battery energises MG1 (Motor/Generator 1) and uses that to spin the ICE up to 1,000rpm before supplying fuel and a spark to ignite it.

8 hours ago, lexuswannabe said:

And what is draining peoples 12v battery surely it can't just be computer gizmos?

First of all is the fact that it's a design fault that should never have got past the drawing board stage - but it did. Lexus/Toyota decided to use low electrical capacity 12V batteries, as indicated by the Ah (Amp-Hour) rating on the label.

I haven't got an LBX so I don't know what capacity the Battery is, but for the sake of this example let's just say 40Ah. This means that it can supply 40A for one hour, or 20A for two hours, or 10A for four hours etc. Even during the middle of the night when the car is 'asleep' there is still power being drawn from the Battery to supply the intruder alarm, the radio presets, seat memory, the clock and so on. This is referred to as the 'quiescent' current draw and most modern cars seem to be in the 50 to 70mA (milliamps or 0.05 to 0.07A) range; anything more could possibly indicate a fault and is then known as a 'parasitic' current draw.

So, if we assume a brand new and fully charged Battery we can then say 40Ah divided by 0.05A = 800 hours (which is 33.3 days or 4.76 weeks) to go from fully charged to fully discharged if the car isn't touched. However, this is a theoretical maximum and various things will mean that you never see this in reality. Also, don't forget that the Battery will be too low to start the car long before it becomes fully discharged, so the 33.3 days will probably drop into the twenty-something range of 'useable' days. Plus, each time it does go flat it damages the plates and loses a little bit more capacity.

You can now perhaps see why it's so important to use the car regularly or to trickle charge it. As I've said before, hybrids do not suit everybody and if your driving patterns mean either short runs and/or long periods of inactivity then a conventional ICE car may be more suitable for you (by which I mean in general, not you personally).

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